Successful measures

Resistant bacteria remain in hospital for years

Resistant bacteria also establish themselves in hospitals for years, as AGES experts have now discovered.

(Bild: Photograph © Spotmatik)

Dangerous bacteria that are resistant to most antibiotics can "hang around" in hospitals for years. Following increased, prolonged outbreaks in a hospital in Upper Austria, experts from the Austrian Agency for Food Safety and Health (AGES) sequenced germs and were able to identify the causes. Countermeasures were successful.

"In spring 2022, an increase in infections with metallo-beta-lactamase-producing Pseudomonas aeruginosa germs (MBLA-Pa) was discovered at a hospital in Upper Austria," wrote the scientists with first author Adriana Cabal from the Institute of Medical Microbiology and Hygiene at AGES and their co-authors in "Microbiology Spectrum" of the American Society for Microbiology (DOI: 10.1128/spectrum.00740-24).

Increased mortality
Bacteria that produce so-called beta-lactamases protect themselves against antibiotics and are resistant. This leads to increased mortality in the event of infections in seriously ill patients. Drug treatment options are significantly limited.

According to the German Robert Koch Institute, Pseudomonas aeruginosa germs are among the "most common causes of hospital-acquired pneumonia during (artificial) ventilation, wound and urinary tract infections worldwide." They can also cause life-threatening sepsis.

"Relationships" investigated
Due to the increased incidence of Pseudomonas aeruginosa infections in the hospital in Upper Austria, it was decided to conduct an intensive investigation into the situation. Initially, the focus was on all cases between 2020 and 2023, then the surveys were extended to 2017. It was possible to examine 54 germ samples from patients and eight isolates from the hospital. The genomes of the bacteria were sequenced to clarify their "relationships".

The results: All but nine of the germ isolates belonged to three clusters of Pseudomonas aeruginosa pathogens with resistance genes. The researchers also discovered the possible ways in which the germs spread. "The most likely source of infection for cluster 1 (...) and cluster 2 (...) were (water; note) drains in the intensive care unit (ICU) washroom. The cluster 3 (bacterial; note) clone may have originated in the urology ward in 2020 and spread to the ICU years later," the experts stated. Resistant bacteria can establish themselves in the hospital environment for years and cause outbreaks.

Close monitoring
In any case, the experts got the situation under control. "In March 2023, after the application of control measures (handling of clothing, isolation of affected patients, monitoring and daily disinfection), no more metallo-beta-lactamase-producing Pseudomonas germs were detected. The outbreak was considered to be over," the scientific paper states. Monitoring for dangerous germs should be particularly close in intensive care units.